Wind Slab Development at Carson Pass

Location Name: 
Round Top
Region: 
Carson Pass Area
Date and time of observation: 
Tue, 02/28/2012 - 14:00
Location Map: 
United States
38° 40' 9.5196" N, 120° 0' 10.512" W
See map: Google Maps
US


Red Flags: 
Whumphing noises, shooting cracks, or collapsing
Recent loading by new snow, wind, or rain
Observation made by: Professional Observer
Snowpit Observations
More detailed information about the snowpack: 

~20cm of new snow on slopes sheltered from the wind, with old tracks still showing. On wind loaded slopes, 50cm+ new snow observed.

Wind slab observed above lower density new snow, with cracking even on low angle terrain. No whumphing or collapse observed.

Video: 1 of 3 very sensitive PSTs on wind loaded test slope at provided lat/long. PST 2/100 (END), PST 5/100(END), and PST 15/100 (END) - all on lower density storm snow with 60cm of soft wind slab on top. 2x ECTPV at same height in same location.

Faceted layer beneath new snow observed in this area, remains quite uncohesive compared to snow above and below it. However, cracking was limited to new snow. No whumphing or collapse of faceted layer observed.

Weather Observations
Blowing Snow: 
Yes
Air temperature: 
Below Freezing
Wind Speed: 
Moderate
Precipitation: 
None
Air temperature trend: 
Static
Wind Direction: 
West
Accumulation rate: 
None
More detailed information about the weather: 

A few breaks in the clouds allowed unobstructed views of surrounding slopes - no natural avalanche activity observed. Current wind loading observed throughout the Carson Pass area. Snow remains cold and unconsolidated and available for continued wind transport.